WA- By Ashley Bach, Seattle Times Eastside

Corrosion starting decades ago in a steel pipe led to a natural-gas explosion last fall that killed a 68-year-old Bellevue woman and destroyed her home, state utility-commission engineers said yesterday.

The gas line began to rust sometime before a corrosion-protection system was installed in the early 1980s, and the corrosion caused a leak that spread gas in the home of Frances Schmitz last September, state engineers said. The gas ignited, and Schmitz was critically burned in the explosion. She died three weeks later.

Days after the explosion, the Washington Utilities and Transportation Commission (WUTC) said that a miswired electrical device could have

contributed to the pipe’s corrosion, and Schmitz’s neighbors in the Spiritridge community said they were worried about their safety.

Yesterday, the WUTC engineers said the miswired device, called a rectifier, was not a factor in the gas leak. But they recommended a $125,000 fine against Puget Sound Energy (PSE), the gas line’s owner, for miswiring the device, which was designed to prevent corrosion.

The WUTC staff also recommended that PSE check all steel gas lines that had no corrosion protection for at least five years. Without the protection in place, even temporarily, some of the pipes could have corroded over time, though the engineers said residents were not in danger.

“If the company follows our recommendations, we’ll continue to have a safe system,” said Tim Sweeney, WUTC spokesman.

PSE officials said they agreed that long-term corrosion caused the gas leak, but they did not commit to a review of their steel pipes.

“We believe through our routine inspection activities, anything like this [corrosion] would have surfaced already … but we need to better understand what [the state engineers’] concerns are,” said Duane Henderson, director of PSE safety and operation services.

Schmitz’s family sued PSE in March, alleging the company did not do enough to stop the leak. The family’s attorney, David Beninger of Seattle, said he disagreed with the state engineers’ findings.

The long-term corrosion was the primary cause of the gas leak, he said, but the miswired rectifier was a contributing cause. The pipe was already heavily rusted, but the miswired device accelerated the corrosion, Beninger said.

“Dealing with the most obvious [factor] is often the easiest, but not always the best solution,” he said.

PSE officials and WUTC engineers said the miswired rectifier was not a cause of the leak.

PSE will officially respond to the findings in the next month, and the three-member state utility commission will make a final decision on the leak’s cause and any fines this fall.